The East Indian varieties are extremely variable in length, and also in relation to the quantity of weak fibres; the properties common to almost the whole being brown colour, and dirty and rough character of the cotton. It is chiefly used in Rossendale, Bury and Oldham for coarse counts.
In the medium trade the fibre is subjected to no fewer than nine processes (each different, and sometimes duplicated or triplicated) before it arrives at the form of even thread known as yarn. In the fine trade two or three additional processes are added.
PLATE I.—PLAN OF SHED. To face pp. 16 and 18.
The spinning department, to describe it briefly, consists of:—
1. Mixing the cotton in stacks to secure thorough blending of various qualities, and elimination of the unevenness present in different bales or parts of one bale. Then commence processes for cleansing, viz.:—
2. Opening or passing the matted pieces of the bales through a series of armed beaters having the functions of both separating the material into small flakes and removing the heavier impurities contained in it, such as sand and seeds.
3. Scutching.—In this process a wing beater, revolving at a speed of 11/1500 revolutions per minute, removes the remainder of the heavy dirt, delivering the material in the form of a lap or roll of cotton. This process is repeated.
4. Carding.—Here, by means of revolving cylinders covered with fine wire teeth, and combing the cotton against other cylinders or plates similarly covered, the light impurities—leaf, dust, short and weak fibres—are extracted, and the lap attenuated into a thin sliver, in which the fibres are laid in such a position as to be easily drawn parallel at the drawing process. These four kinds of cleaning machinery remove impurities and other matter foreign to the nature of cotton, to the extent of about 10 per cent., taking middling American cotton.
5. Combing.—The long fibres are here separated from the short, thus enabling a portion of the cotton to be used for spinning finer yarns than the bulk would spin. It is only in the mills spinning yarns above, say 80’s, that this process is found; in ordinary, the custom is to go direct from carding to
6. Drawing.—A simple process repeated for yarn up to 30’s, used three times up to 60’s, and four processes are used above this. The machine has for its object the levelling of the slivers, six of which are placed together and drawn six times the original length. When this has been repeated once or twice, the sliver becomes very even and silky in consequence of all the fibres having had the curl taken out and been laid parallel to each other.
7. Slubbing; 8. Intermediate; and 9. Roving.—These frames are all constructed on one principle, and have for their object the gradual diminution of the thickness of the sliver, which at these processes is attenuated so much as to require twisting to keep it from breaking at the succeeding process. An additional jack roving frame is used at mills making over 100’s yarn.
10. Spinning completes the object of all the former machines—i.e., to produce a level clean thread, free from unevenness in every respect.
Four sorts of machines are used for completing the attenuation—the self-actor mule, ring frame, hand mule, and throstle frame. The two latter are fast disappearing in consequence of the great improvements over the hand mule recently made in the self-actor mule, so as to spin fine counts up to 300’s, and in the increased output of the ring over the throstle frame. The mule is automatic in all its movements for spinning the yarn and winding it on the spindle in the form of a cop—i.e., a cylindrical coil of yarn, cone-shaped at each end. In this machine the spinning is intermittent—i.e., for a few seconds the different portions of the machines are engaged in drawing out the roving to the required fineness until about 64 inches have been spun, the slack being taken up by a moving carriage bearing the spindles, then a few seconds are employed in drawing back the carriage and winding the yarn on the spindles. The ring frame is a constant spinner, and as fast as the yarn is spun it is wound on a bobbin, while the necessary twist is put in by a traveller shaped [C] revolving round a ring. It will thus be seen that the ring frame is only suited for warp yarns, mainly in consequence of having to use a bobbin, which of course requires modifications in the shuttle and box of the loom, and even then is disadvantageous. The ring frame is suitable and preferable for warp yarn up to 40’s, where the spinner also reels, warps or weaves his own spinning. The mule spins both weft and twist. Throstle twist (or, as it is called when reeled or warped by the spinner, water twist) is generally admitted to be the evenest and roundest thread, ring twist being next best, and mule yarn inferior to both. Mule yarn, however, possesses an elasticity which neither of these can boast of.